Health

Effects of human growth hormone in men over 60 years old

Article Abstract:

The body changes in middle and late adulthood, gradually decreasing in lean body mass while the mass of adipose tissue (fat) increases. Although such alterations are generally considered an inevitable aspect of the aging process, it is possible that decreases in the level of growth hormone (a class of hormones with many physiological effects) are contributory. A greater proportion of men over 60 years of age have levels of insulin-like growth factor I (IGF-I, or somatomedin C, produced in the liver and elsewhere) lower than 350 U per liter, while such low levels are found in barely five percent of men between 20 and 40. IGF-I is the substance that actually mediates growth hormone's effects. To see whether administration of growth hormone could partly reverse the bodily changes associated with aging, it was provided to healthy men (12 subjects) aged 61 or older for six months. The hormone was self-administered three times weekly by subcutaneous (under the skin) injection. Nine men of similar age and health constituted a control group who received no injections. All subjects maintained a controlled diet. Subjects were examined regularly throughout the study. Results showed that all the men remained in good health, although the IGF-I group members had higher average systolic blood pressure (pressure during the contracting phase of the heart's cycle) and higher blood glucose (sugar) levels at the end of the experiment than at its onset. The concentration of IGF-I in blood rose dramatically (from a range of 200 to 250 U per liter during baseline, to approximately 830 U per liter). No weight changes were noted in either group, but body composition altered for the men receiving hormone. Lean body mass and density of the lumbar vertebrae increased by 8.8 percent and 1.6 percent respectively, while the mass of adipose tissue decreased by 14.4 percent. Skin thickness had also increased. No such changes were found among men who did not take IGF-I. Since roughly one third of all men in the 60- to 80-year age group have levels of IGF-I as low as these subjects, results should not be generalized to men with higher concentrations, or to women. The changes noted were of the order of magnitude associated with 10 to 20 years of aging. (Consumer Summary produced by Reliance Medical Information, Inc.)

Gigantism due to pituitary mammosomatotroph hyperplasia

Article Abstract:

Increased secretion of growth hormone during childhood causes increased height and size. Abnormal body proportions occur when there is increased growth hormone in early childhood. A child with gigantism usually has enlarged hands and feet, thickened soft tissue, projected jaws with abnormal facial configuration, and coarse facial features. An unusual case is described of a three-year-old girl with a diagnosis of gigantism that occurred during infancy and a rare condition known as mammosomatotroph pituitary hyperplasia, growth acceleration of the cells that produce growth hormone and prolactin, the hormone necessary for milk production in females. (Consumer Summary produced by Reliance Medical Information, Inc.)